Re: [fpc-pascal] Nesting
Juha Manninen (gmail) escreveu:
A new Lazarus review :
http://delphimax.wordpress.com/2010/09/13/freepascal-and-lazarus-success-or-
failure/
has this comment about Lazarus source:
---
Abundant use of the Exit() command instead of nesting code in If/then/else. It
has been proven (last time in Delphi Informant Magazine) that allowing a
method to nest itself out makes faster code. It is also easier to read and
study. Exit should of course be used (it must be used in many situations) but
prudently.
---
Does nesting really create faster code?
If i understand right what you mean by nesting, the produced code is
equal at least in my simple test. See attached.
I dont know for more complex situations
Luiz
program template;
{$Mode ObjFpc}
procedure DoIt;
begin
WriteLn('DoIt');
end;
procedure UseExit(i: Integer);
begin
if i = 0 then Exit;
DoIt;
end;
procedure DontUseExit(i: Integer);
begin
if i <> 0 then
DoIt;
end;
begin //Main
UseExit(1);
DontUseExit(1);
end..file "asmExit.pas"
.section .text
.section .text
.balign 4
.balign 4
# [asmExit.pas]
# [5] begin
.globl P$TEMPLATE_DOIT
P$TEMPLATE_DOIT:
# Temps allocated between ebp-4 and ebp+0
pushl %ebp
movl%esp,%ebp
subl$4,%esp
movl%ebx,-4(%ebp)
# [6] WriteLn('DoIt');
callfpc_get_output
movl%eax,%ebx
movl$_$PROGRAM$_L10,%ecx
movl%ebx,%edx
movl$0,%eax
callfpc_write_text_shortstr
callFPC_IOCHECK
movl%ebx,%eax
callfpc_writeln_end
callFPC_IOCHECK
# [7] end;
movl-4(%ebp),%ebx
leave
ret
.section .text
.balign 4
.balign 4
# [10] begin
.globl P$TEMPLATE_USEEXIT$LONGINT
P$TEMPLATE_USEEXIT$LONGINT:
# Temps allocated between ebp-4 and ebp-4
pushl %ebp
movl%esp,%ebp
subl$4,%esp
# Var i located at ebp-4
movl%eax,-4(%ebp)
# [11] if i = 0 then Exit;
testl %eax,%eax
je .L22
# [12] DoIt;
callP$TEMPLATE_DOIT
# [13] DoIt;
callP$TEMPLATE_DOIT
# [14] DoIt;
callP$TEMPLATE_DOIT
# [15] DoIt;
callP$TEMPLATE_DOIT
# [16] DoIt;
callP$TEMPLATE_DOIT
# [17] DoIt;
callP$TEMPLATE_DOIT
# [18] DoIt;
callP$TEMPLATE_DOIT
# [19] DoIt;
callP$TEMPLATE_DOIT
# [20] DoIt;
callP$TEMPLATE_DOIT
# [21] DoIt;
callP$TEMPLATE_DOIT
.L22:
# [22] end;
leave
ret
.section .text
.balign 4
.balign 4
# [25] begin
.globl P$TEMPLATE_DONTUSEEXIT$LONGINT
P$TEMPLATE_DONTUSEEXIT$LONGINT:
# Temps allocated between ebp-4 and ebp-4
pushl %ebp
movl%esp,%ebp
subl$4,%esp
# Var i located at ebp-4
movl%eax,-4(%ebp)
# [26] if i <> 0 then
testl %eax,%eax
je .L34
# [28] DoIt;
callP$TEMPLATE_DOIT
# [29] DoIt;
callP$TEMPLATE_DOIT
# [30] DoIt;
callP$TEMPLATE_DOIT
# [31] DoIt;
callP$TEMPLATE_DOIT
# [32] DoIt;
callP$TEMPLATE_DOIT
# [33] DoIt;
callP$TEMPLATE_DOIT
# [34] DoIt;
callP$TEMPLATE_DOIT
# [35] DoIt;
callP$TEMPLATE_DOIT
# [36] DoIt;
callP$TEMPLATE_DOIT
# [37] DoIt;
callP$TEMPLATE_DOIT
.L34:
# [39] end;
leave
ret
.section .text
.balign 4
.balign 4
# [41] begin //Main
.globl PASCALMAIN
PASCALMAIN:
.globl _main
_main:
# Temps allocated between ebp+0 and ebp+0
pushl %ebp
movl%esp,%ebp
callFPC_INITIALIZEUNITS
# [42] UseExit(1);
movl$1,%eax
callP$TEMPLATE_USEEXIT$LONGINT
# [43] DontUseExit(1);
movl$1,%eax
callP$TEMPLATE_DONTUSEEXIT$LONGINT
# [44] end.
callFPC_DO_EXIT
leave
ret
.balign 4
.section .data
.ascii "FPC 2.0.4 [2006/08/21] for i386 - Win32"
.balign 16
.balign 16
.globl THREADVARLIST_P$TEMPLATE
THREADVARLIST_P$TEMPLATE:
.long 0
.balign 4
.globl FPC_THREADVARTABLES
FPC_THREADVARTABLES:
.long 3
.long THREADVARLIST_SYSTEM
.long THREADVARLIST_OBJPAS
.long THREADVARLIST_P$TEMPLATE
.balign 4
.globl FPC_RESOURCESTRINGTABLES
FPC_RESOURCESTRINGTABLES:
.long 0
.balign 4
.globl INITFINAL
INITFINAL:
.long 2,0
.long INIT$_SYSTEM
.long FINALIZE$_SYSTEM
.long INIT$_OBJPAS
.long FINALIZE$_OBJPAS
.section .data
.balign 4
.globl __stklen
__stklen:
.long 262144
.section .data
.balign 4
.globl __heapsize
__heapsize:
.long 0
.section .data
.section .data
.balign 4
.globl _$PROGRAM$_L10
_$PROGRAM$_L10:
.ascii "\004DoIt\000"
.section .data
.section .data
.section .bss
__
[fpc-pascal] Interface with NASM
I need to teach assembler, and the easiest way would be to create a driver
and simple I/O library in high level language that can be called from
assembler so that students can focus in programming with assembler more than
dealing with system specific features. It's been quite a while since I go
down to this level, so I might miss something.
Here's the IO library (asmio.pas):
unit asmio;
interface
procedure printc(const c: Char); pascal;
procedure printi(const i: LongInt); pascal;
implementation
procedure printc(const c: Char); pascal; [public, alias: 'printc'];
begin
Write(c);
end;
procedure printi(const i: LongInt); pascal; [public, alias: 'printi'];
begin
Write(i);
end;
end.
The driver program (driver.pas):
program driver;
{$L asmio.o}
{$L test.o}
procedure tes; pascal; external name 'tes';
begin
tes;
end.
And example assembler program which suppose to print 'A' (test.asm):
[bits 32]
extern printc,printi
segment .text
global tes
tes:
push ebp
mov ebp,esp
push 65
call printc
leave
ret
build command:
nasm -f coff test.asm
fpc asmio.pas
fpc -o test driver.pas
As you can see, I didn't use any optimizations because AFAIR FPC would
change parameter passing mechanism when a certain optimizations are
performed. Of course if it works I won't ask here, but it doesn't. I got
access violation instead. However changing the driver program to:
procedure printc(const c: Char); pascal; external name 'printc';
begin
printc('A');
end.
generates the same instruction sequence for calling printc:
push 65
call printc
I've tried omitting the stackframe (with the corresponding modifier in
driver program) but no effect. I wonder where my mistake is...
Additional information:
I've made it to work for non IO functions
--
View this message in context:
http://free-pascal-general.1045716.n5.nabble.com/Interface-with-NASM-tp2838671p2838671.html
Sent from the Free Pascal - General mailing list archive at Nabble.com.
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Re: [fpc-pascal] Basics of profiling -- some comments on fpprofiler bugs
On Mon, 2010-09-06 at 16:58 +0300, Žilvinas Ledas wrote: > On 2010-09-06 15:48, Darius Blaszyk wrote: > > On Mon, 2010-09-06 at 13:01 +0200, Graeme Geldenhuys wrote: > >> Recently I took a look at Darius's old project 'fpprofiler. Links > >> below. It was over 2 years since anybody worked on it, and riddled > >> with bugs. I fixed all memory leaks, added some improvements, and used > >> the new fcl-passrc code included with FPC Trunk (though it only uses > >> the tokenizer for speed reasons, so FPC 2.4.x should work to - maybe > >> with minor one line code change). > > I've tested fpprofiler on FPC 2.4 and it works, provided the fcl-passrc > > is from 2.5.1. I'll add this folder as external to the SVN repository. > Few notes (parts that need some improvement): > 1) fpp.pp needs at least tkAsm in "case tokenlist[i].token of" in > "procedure ModifyCode(AFileName: string; tokenlist: TPasTokenList);" > 2) it works wrong with ifdef's (it leaves only ELSE code) -- (I modified > my copy to output comments as well and had to "modify" pscanner.pp to > have directives as simple comments); > 3) in "procedure TPasTokenList.SaveToFile(const AFileName: string);" no > need for writeLN's - writes are enough; > 4) Asm procedures are handeled wrong (fpprof_exit_profile; is inserted > before end;) > function IsCPUID_Available : Boolean; register; assembler; > asm >... > end; > 5) records with cases (or some other type) is handeled wrong > (fpprof_exit_profile; is inserted before end;) -- I don't remember what > type it was exactly. > > In my opinion 2) is the biggest problem now :) > > P. S. These comments are with Graemes changes. > P. P. S. Good luck with improvements and updates! Could you please create patches or at least some simple testcases for each described issue? I will add them to SVN to prevent regressions in the future. Please post them on mantis. Darius ___ fpc-pascal maillist - fpc-pascal@lists.freepascal.org http://lists.freepascal.org/mailman/listinfo/fpc-pascal
Re: [fpc-pascal] Help translating C++ to Object Pascal
On Tue, 14 Sep 2010 11:50:31 +0200 Graeme Geldenhuys wrote: > Hi, > > In a C++ method as shown below, does the '... return True;' immediately > exit the HandleClientMessage method Yes. R. -- A: Because it messes up the order in which people normally read text. Q: Why is top-posting such a bad thing? A: Top-posting. Q: What is the most annoying thing in e-mail? ___ fpc-pascal maillist - fpc-pascal@lists.freepascal.org http://lists.freepascal.org/mailman/listinfo/fpc-pascal
Re: [fpc-pascal] Help translating C++ to Object Pascal
On Tue, 14 Sep 2010 11:50:31 +0200, Graeme Geldenhuys wrote about [fpc-pascal] Help translating C++ to Object Pascal: > In a C++ method as shown below, does the '... return True;' > immediately exit the HandleClientMessage method, or will it still > continue processing the remainder of the method (just exiting the > current code block)? It will return directly to the calling routine. The following statement: > return OXCompositeFrame::HandleClientMessage(event); will be ignored. -- Regards, Dave [RLU #314465] *-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-* david.w.n...@ntlworld.com (David W Noon) *-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-* signature.asc Description: PGP signature ___ fpc-pascal maillist - fpc-pascal@lists.freepascal.org http://lists.freepascal.org/mailman/listinfo/fpc-pascal
[fpc-pascal] heap size & free heap
Hi Maybe someone here knows... I built Lazarus with "-gh", started it and closed without doing anything else. --- Heap dump by heaptrc unit 717866 memory blocks allocated : 81646458/83984784 717866 memory blocks freed : 81646458/83984784 0 unfreed memory blocks : 0 True heap size : 851968 True free heap : 942784 Should be : 851968 --- What are the 3 last lines about? I am running on 64-bit Linux. Juha ___ fpc-pascal maillist - fpc-pascal@lists.freepascal.org http://lists.freepascal.org/mailman/listinfo/fpc-pascal
[fpc-pascal] Help translating C++ to Object Pascal
Hi,
In a C++ method as shown below, does the '... return True;' immediately
exit the HandleClientMessage method, or will it still continue processing
the remainder of the method (just exiting the current code block)?
int OXMainFrame::HandleClientMessage(XClientMessageEvent *event) {
if (_dndManager) {
if (_dndManager->HandleClientMessage(event)) return True;
}
if ((event->format == 32) && (event->data.l[0] == WM_DELETE_WINDOW)) {
CloseWindow();
return True;
}
return OXCompositeFrame::HandleClientMessage(event);
}
Regards,
- Graeme -
--
fpGUI Toolkit - a cross-platform GUI toolkit using Free Pascal
http://opensoft.homeip.net/fpgui/
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[fpc-pascal] Re: Nesting
I sometimes use that kind of Exit because it's cheaper in code, though it makes the code flow less structured. Probably because C family bad coding doctrine (my university is a C family slave). But when I'm in full consciousness, I use if/else. -- View this message in context: http://free-pascal-general.1045716.n5.nabble.com/Nesting-tp2837567p2838663.html Sent from the Free Pascal - General mailing list archive at Nabble.com. ___ fpc-pascal maillist - fpc-pascal@lists.freepascal.org http://lists.freepascal.org/mailman/listinfo/fpc-pascal
Re: [fpc-pascal] Question mark?
Does it work without {$ Codepage UTF8} ?
--
Felipe Monteiro de Carvalho
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Re: [fpc-pascal] Basics of profiling -- some comments on fpprofiler bugs
On Mon, 2010-09-06 at 16:58 +0300, Žilvinas Ledas wrote: > 3) in "procedure TPasTokenList.SaveToFile(const AFileName: string);" > no > need for writeLN's - writes are enough; Fixed in rev2492 ___ fpc-pascal maillist - fpc-pascal@lists.freepascal.org http://lists.freepascal.org/mailman/listinfo/fpc-pascal
Re: [fpc-pascal] Interface with NASM
Hi, I've played around with your code and didn't get usefull results either at first glance. Instead of putting the printc test into driver, I've wrote a pure pascal unit which does the same as your test.asm, compiled it, disassembled it and modfied the nasm program. That worked. I'm on a different target machine and pascal calling convention doesn't work at all so this may not be usefull for you, but at least there is a chance it may be, so here is the pure pascal test.asm. If this doesn't link correctly it may be another Problem (!so Compiler Version/svn revision and Target would be good to know!) --- unit testp; interface procedure tes; pascal; implementation procedure printchar( c: Char ); pascal; external name 'printc'; procedure tes; pascal; [public, alias: 'tes']; begin printchar( 'A' ); end; end. --- Btw. It would be very interesting to know the solution for your Problem if its already fixed :) ___ fpc-pascal maillist - fpc-pascal@lists.freepascal.org http://lists.freepascal.org/mailman/listinfo/fpc-pascal
Re: [fpc-pascal] Help translating C++ to Object Pascal
Am 14.09.2010 11:50, schrieb Graeme Geldenhuys:
Hi,
In a C++ method as shown below, does the '... return True;' immediately
exit the HandleClientMessage method, or will it still continue processing
the remainder of the method (just exiting the current code block)?
int OXMainFrame::HandleClientMessage(XClientMessageEvent *event) {
if (_dndManager) {
if (_dndManager->HandleClientMessage(event)) return True;
}
if ((event->format == 32)&& (event->data.l[0] == WM_DELETE_WINDOW)) {
CloseWindow();
return True;
}
return OXCompositeFrame::HandleClientMessage(event);
}
"return Something;" in C/C++ is equivalent to "Exit(Something);" in
FPC's Pascal.
Regards,
Sven
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Re: [fpc-pascal] Help translating C++ to Object Pascal
Thanks to all that replied. My C/C++ is a bit rusty. :) Regards, - Graeme - -- fpGUI Toolkit - a cross-platform GUI toolkit using Free Pascal http://opensoft.homeip.net/fpgui/ ___ fpc-pascal maillist - fpc-pascal@lists.freepascal.org http://lists.freepascal.org/mailman/listinfo/fpc-pascal
